1. Field
The presently disclosed subject matter relates to reflective typed wavelength converting modules and semiconductor light-emitting apparatuses using the wavelength converting module, and more particularly to the reflective typed wavelength converting modules, which can emit mixture lights having substantially various uniform color tones and a high light-intensity using an exciting light emitted from a semiconductor light source and the semiconductor light-emitting apparatuses using the wavelength converting module, which can emit various color lights having a high light-intensity and a substantially uniform color tone including a substantially white light in order to be able to be used for vehicle lamp such as a headlight, general lighting, a stage light, a street light, a projector, etc.
2. Description of the Related Art
A range of application for semiconductor light-emitting apparatuses, which may emit various color lights by combining a wavelength converting material such as a phosphor layer with a semiconductor light-emitting device such as an LED, have expanded to various fields such as vehicle lamps, general lighting, street lighting and the like, because brightness of the semiconductor light-emitting apparatuses have improved. As a type of such the light-emitting apparatuses, a transmission type, which emits a mixture light having a color tone from a light-emitting surface of the phosphor layer by entering an exciting light into the phosphor layer from an incident surface located on opposite side of the light-emitting surface, is well known.
As another type, a reflective type, which emits a mixture light having a color tone from a light-emitting surface of a phosphor plate including a reflector surface by entering an exciting light into the phosphor plate from an incident surface located on the same reflector surface and by reflecting the mixture light with the reflector surface, is well known. The reflective type may emit the mixture light having a high light-intensity mainly by using the mixture light reflected from the reflector surface, and therefore has been expected to expand in application.
FIG. 13 is a schematic structural view showing a conventional semiconductor light source apparatus of the reflective type disclosed in Patent document No. 1 (Japanese Patent Application Laid Open JP2012-64484), and another conventional light source apparatus similar to the conventional semiconductor light source apparatus is also disclosed Patent document No. 2 (U.S. Pat. No. 8,556,437). The patent documents No. 1 and No. 2 are disclosed by a same inventor, and are owned by Applicant of this disclosed subject matter.
The conventional semiconductor light source apparatus includes: a reflector 84; a phosphor ceramic 83 arranged on the reflector 84 via a transparent adhesive material 85; a semiconductor light-emitting device 81 having an optical axis 82 located adjacent the phosphor ceramic 83, the optical axis 82 intersecting with the phosphor ceramic 83; a mixture light 86 having a color tone emitted from a light-emitting surface of the phosphor ceramic 83 by entering an exciting light emitted from the semiconductor light-emitting device 81 into the phosphor ceramic 83 and by reflecting the mixture light using at least one of the reflector 84, the transparent adhesive material 85 and the phosphor ceramic 83; and an optical lens 87 located in a direction of the light-emitting surface of the phosphor ceramic 83, and projecting a prescribed light distribution pattern using the mixture light 86.
In the conventional semiconductor light source apparatus 80, a heat generated from the phosphor ceramic 83 by the exciting light emitted from the semiconductor light-emitting device 81 may mainly radiate from the reflector 84, which is made from a metallic plate, and therefore may not degrade the phosphor ceramic 83. However, because the heat generated from the phosphor ceramic 83 may degrade the transparent adhesive material 85, an adhesive intensity between the phosphor ceramic 83 and the reflector 84 may degrade and a reflectivity of the reflector 84 may decrease. Hence, the heat generated from the phosphor ceramic 83 may cause optical characteristics of the semiconductor light source apparatus 80 to gradually deteriorate.
Accordingly, even when a high power semiconductor light source is used under a large current as a light source, reflective type semiconductor light source apparatuses that can emit various color lights having high brightness and can efficiently radiate a heat, is disclosed in Patent document No. 3 (U.S. patent application Ser. No. 14/943,240) by the inventor of this disclosed subject matter. By contrast with reflective type light source apparatuses, transmission type semiconductor light source apparatus are also disclosed by the inventor of this disclosed subject matter.
A conventional transmission type semiconductor light-emitting apparatus that may prevent a color variation, is disclosed in Patent document No. 4 (Japanese Patent Application Laid Open JP2013-102078) by the inventor of this disclosed subject matter, and which is owned by Applicant of this disclosed subject matter. FIG. 14 is a schematic explanatory perspective view showing the conventional transmission type semiconductor light-emitting apparatus disclosed in Patent document No. 4. The conventional semiconductor light-emitting apparatus 90 includes: a semiconductor light source 95 having a light beam diameter 95D, and a wavelength converting plate 92 including a plurality of wavelength converting chips 97 and a plurality of plates 96, which divides the wavelength converting plate 92 into the plurality of wavelength converting chips 97.
In the conventional semiconductor light-emitting apparatus 90, a diameter 95D of the light beam emitted from the semiconductor light source 95 becomes smaller than each of widths in directions of X-direction and Y-direction of each of the wavelength converting chips 97 so that the light beam emitted from the semiconductor light source 95 can enter into each of incident surfaces of the wavelength converting chips 97. Additionally, the plurality of plates 96 are made from a metallic plate having a high reflectivity such as a silver, aluminum and the like so that the light beam entering into each of the incident surfaces of the wavelength converting chips 97 may be emitted from a respective one of light-emitting surfaces of the wavelength converting chips 97. Thereby, the conventional semiconductor light-emitting apparatus 90 may prevent the color variation such as a yellow ring even when each of the wavelength converting chips 97 include a yellow phosphor.
Recently, vehicle headlights using a semiconductor light source and a mirror that can provide various light distribution patterns for drivers and headlight systems using the headlights that can vary a light distribution pattern so that the drivers can drive a motor vehicle safely in accordance with surroundings such as an oncoming vehicle, a forward travelling vehicle, a road and the like have been developed. Such a headlight system is disclosed, for example, in Patent document No. 5, which is owned by Applicant of this disclosed subject matter.
When the vehicle headlights use a semiconductor light source and a mirror to provide various light distribution patterns for the drivers, light emitted from the semiconductor light source may scan on the wavelength converting plate 92 including the plurality of wavelength converting chips 97. In this case, a part of the light emitted from the semiconductor light source hits on the plurality of plate 96 and may return toward the semiconductor light source 95. Accordingly, when the vehicle headlights having such a structure, in which the light scans on the wavelength converting plate 92, use the wavelength converting plate 92 including the plurality of wavelength converting chips 97, the vehicle headlights may decrease a light-emitting efficiency thereof.
The above-referenced Patent Documents and additional Patent Documents are listed below and are hereby incorporated with their English abstracts in their entireties.    1. Patent document No. 1: Japanese Patent Application Laid Open JP2012-64484    2. Patent document No. 2: U.S. Pat. No. 8,556,437    3. Patent document No. 3: U.S. patent application Ser. No. 14/943,240    4. Patent document No. 4: Japanese Patent Application Laid Open JP2013-102078    5. Patent document No. 5: U.S. Pat. No. 8,956,025    6. Patent document No. 6: U.S. Patent Publication No. 2015-0372200-A1    7. Patent document No. 7: U.S. patent application Ser. No. 14/937,823    8. Patent document No. 8: U.S. Patent Publication No. 2015-0175054-A1
The disclosed subject matter has been devised to consider the above and other problems, characteristics and features. Thus, an embodiment of the disclosed subject matter can include semiconductor light-emitting apparatuses using a wavelength converting module, which can emit various color lights having a substantially uniform color tone and a high light-intensity and can efficiently radiate a heat, even when a high power semiconductor light source such a laser device is used as a light source. In this case, an exciting light emitted from the laser device can be efficiently wavelength-converted by the wavelength converting module without a reduction of light intensity, because a phosphor layer included in the wavelength converting module is substantially located on a base board having a high radiating-efficiency, and also the wavelength converting module can enable the phosphor layer not to include a substantially resin component.
In addition, the base board can connect a radiating fin in an opposite direction of the phosphor layer as a radiator to further improve a radiating efficiency and permanence of the phosphor layer even when the high power semiconductor light source such as the laser device is used as a light source. Thus, the semiconductor light-emitting apparatuses can also emit the various color lights having the substantially uniform color tone and a high light-intensity via an optical device such as a projector lens, and therefore can be employed for various lighting units such as a vehicle headlight, general lighting, a stage light, a street light, a projector, etc.